Wowbagger
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We all know 3V would still make a better KNIFE
and
5160 would make a better car spring (well . . . actually . . . truck spring (real cars these days use independent suspension)).
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Is cpm 3v if heat treated right as tough as 5160
- Thread starter pandaatkins
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and
5160 would make a better car spring (well . . . actually . . . truck spring (real cars these days use independent suspension)).
Only if we know what the intended use for the knife will be. As far as pure toughness goes, my guess would be that 5160 is going to be tougher because there is less carbon, less alloying elements, therefore finer and more homogeneous grain structure, which is correlated with higher toughness.
Wowbagger
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sounds boring.
ooooh . . . I DO like fine grain and homogeneous grain
sounds GREAT !
Ohhhh I'm SO confused now.
"3V" sounds cooler than "5160"
I'm going with 3V
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Finer grain structure than a particle steel? Citation please.
https://www.materials.sandvik/en/pr...l-knowledge/important-factors/microstructure/
Unfourtunately, this is the best I can find now, you can see, that the 12c27 (simple carbon steel like 5160 should be even finer) has a finer grain structure than the powdered steel shown here. I have seen better comparisons between the grain sizes of carbon steel vs some cpm steel, but can't find them now. Powdering does immensely refine the grain structure if you compare it to the same composition of a non-powdered steel (like d2 vs cpm d2), but it still doesn't reach the levels of simple carbon steels.
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What is the average particle size of 3v? What is the average particle size of 5160?
The sandvik steels that are used in razor blades are extremely fine grained, your stating that 5160 is finer? Without citation I call BS. Prove what you say with facts.
hugofeynman
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Does cpm3v makes fine blades? Yes. Is cpm3v one of the toughest steels available for cutlery? No. S7, Infi, A8mod, 5160, 6150, S1 are all much tougher than cpm3v, if heat treated right and if the steel is cut parallel to the rolling direction (like wood, steel has grain, and is much tougher with the grain than perpendicular/transversal to the grain).
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Those steels are tougher at what hardness? Blanket statements like the one you just made are ignorant and incorrect.
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Those gross misinformation some of you are spewing is ridiculous. Those general all encompassing assertions are wrong.
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Yeah, hardness seems pretty key here as I seem to remember that with 3V relatively small changes in hardness make a BIG difference in toughness. IIRC, 3V Charpy tested at 58rc scored something like 110J and at 60rc scored about 58J.
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That's just it, everything is relative. How tough is 5160 at 60 Rockwell? I'm not aware of any official tests so any assertions would be guessing. Which is exactly why blanket statements above from a few posters are silly.
4140 at 30 Rockwell will be tougher then 3v, same can be said for countless other steels RAN SOFT. Run those steels at 60hrc which is perfect for a fixed blade knife and see who's tougher
Also, I feel it's noteworthy to add, I've not seen anyone in this thread say 3v was or is the toughest steel.
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Your numbers are closer to 58 vs 62 Rc: http://www.crucible.com/PDFs/DataSheets2010/ds3Vv1 2015.pdf
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Thank you,
Larrin
! I was a bit hesitant to quote from memory, but nice to see I wasn't too far off.
hugofeynman
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Does the OP mention a specific hardness?
I’m really confident that, in time, Larrins toughness tests will show everyone who’s really Ignorant and who makes Incorrect assumptions regarding steel and Metallurgy.
I firmly believe that cpm3v will have lower toughness (at any hardness) than Larrin’s AEBL measurements, let alone the steels I’ve mentioned! Want to see my theory tested? Ask some cpm3v coupons to someone you think that can heat treat Cpm3v. I can even send you Roman Landes recipe, if you need. I’ve already sent Willie71 some A8mod, Vanadis 4 extra and NZ3 (~S1) so he can make some coupons for Larrin to test, he and Larrin can choose the hardness they want for those coupons. I even sent him a piece of Ultrafort steel, some really expensive Maraging steel that can achieve 60hrc and is used for fencing blades and for state of the art armored vehicles. Now we just need to convince someone who uses good quality 5160 to enter the game.
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Hardness not being asked in the OP has diddly squat to do with an educated respones which would include an answer that discusses hardness. Theorize all you want, making blanket statements makes you look ignorant. You have no data to back up your claims except hot air.
Properly selected alloying promotes higher toughness and grain refinement. 5160 is tougher than 1060 for example. 5160 has lower carbon and less carbide volume going for it. It's also probably easier to get a very fine grain size, but that's a processing issue. 3v has a fair bit of alloying, very fine carbide, and the ability to maintain hardness after tempering over 900 degrees F.
All these steels -- 3V, V4E, 5160, M4, A8(mod) and such -- can make very tough choppers. It all comes down to the heat treat and geometry. I'd go with someone who makes high-performance choppers in steels with heat treats that have proven effective.
Nathan makes awesome choppers in D3V. Not only are they excellent knives, the steel holds up to severe chopping, even through concrete blocks. I think Survive uses that same heat treat.
Some knife makers put out awesome blades in 5160. Some don't. Busse's Infi has proven itself as another excellent and very tough chopper.
If that's not enough toughness, go with high-impact S7. Busse makes S7 choppers (SR77), and I think Survive made big blades in S7, too.
Lots of knife makers can make tough choppers in a variety of steels.
It would be nice if we could just look up the science and find the best steel and the best heat treat in the best geometry for any given task, but that science isn't available to us. So we're stuck with informed opinions.
Nathan makes awesome choppers in D3V. Not only are they excellent knives, the steel holds up to severe chopping, even through concrete blocks. I think Survive uses that same heat treat.
Some knife makers put out awesome blades in 5160. Some don't. Busse's Infi has proven itself as another excellent and very tough chopper.
If that's not enough toughness, go with high-impact S7. Busse makes S7 choppers (SR77), and I think Survive made big blades in S7, too.
Lots of knife makers can make tough choppers in a variety of steels.
It would be nice if we could just look up the science and find the best steel and the best heat treat in the best geometry for any given task, but that science isn't available to us. So we're stuck with informed opinions.
The term grain structure has 2 parts. Grain size and carbide size. 5160 normally has no undissolved carbides, so they are smaller than 3V and AEB-L. Specific information for 3V is sparse on carbide size, but the typical size for CPM type steels is 3 to 6 microns. The carbide size in AEB-L is around 1 micron.
Grain size information for specific CPM steels is also fairly hard to some by. What little I've found puts the grain size in the 35 micron range. Grain size of AEB-L is likely comparable or perhaps a bit finer. Again, information on grain size is scarce. The relatively high austenizing temperatures could be offset by the short recommended hold times. The low alloy steels are easier to manipulate in terms of grain size. Standard heat treatments can produce grain sizes between 22 and 32 microns. Specific treatments for grain size reduction can push it as low as 3 microns. These procedures are uncommon in production knives but more popular for individually made knives.
S7 is listed as tougher than 3V by Crucible by nearly 50%. S1 is tougher than S7. Based on it's similar composition to S7, A8Mod likely has toughness between 3V and S7. It has less carbon, less carbide volume, and can withstand elevated tempering while maintaining relatively high hardness. 5160 has been addressed. 6150 is tougher still, though the two are used for the same purpose at times.
Same hardness comparisons are not as simple as one might think. It may put one steel or the other into an embrittlement range. Some steels may not realisitically reach the same hardness levels.
I feel it necessary to point out that the differences in toughness of 3V at various hardnesses are not due to the hardnesses. The hardness and the toughness differences are due to changes in heat treatment temperatures. Hardness is not the end goal. It is a relatively easily measured indicator that the desired procedure was followed and worked as planned.
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I'll address a few points more in depth in a bit. As a machinist who works in the armor industry I work with lots of steels that are tougher then 3v. Most of which don't make as good a knife because they don't reach the hardness necessary as well the excel at ONLY being tough. A myopic point of view would accept that virtually dozens of steels are "tougher" than 3v that are to soft, corrosion magnets, won't hold an edge worrg crap, and more.